Chapter 21.1, Problem 7CC

Interpretation Introduction

Interpretation:

To draw resonance structure of the enolate that is formed and to explain why enolate formation is nearly complete when sodium ethoxide is used.

Concept introduction:

Keto-enol isomerization is possible when a keto group present in the compound has a movable hydrogen atom in the next carbon attached to the carbonyl group.  This occurs generally in almost all keto compounds where a chemical equilibria is present between the keto and enol form of the compound.  Conversion of keto to its enol form is known as keto-enol tautomerisation.  Deprotonation using base results in the formation of enolate ion.  If the negative charge is delocalized in more number of atoms that resonance structure is more stable.